Relax restricted classes #369

Job	Run time
ruby-versions / Generate Ruby versions	2s
build (2.5, 0.1.7, /tmp/local)	53s
build (2.5, 0.1.7)	34s
build (2.5, 0.2.5, /tmp/local)	52s
build (2.5, 0.2.5)	36s
build (2.6, 0.1.7, /tmp/local)	58s
build (2.6, 0.1.7)	1m 44s
build (2.6, 0.2.5, /tmp/local)	1m 0s
build (2.6, 0.2.5)	38s
build (2.7, 0.1.7, /tmp/local)	56s
build (2.7, 0.1.7)	47s
build (2.7, 0.2.5, /tmp/local)	59s
build (2.7, 0.2.5)	37s
build (3.0, 0.1.7, /tmp/local)	33s
build (3.0, 0.1.7)	22s
build (3.0, 0.2.5, /tmp/local)	30s
build (3.0, 0.2.5)	30s
build (3.1, 0.1.7, /tmp/local)	28s
build (3.1, 0.1.7)	24s
build (3.1, 0.2.5, /tmp/local)	26s
build (3.1, 0.2.5)	24s
build (3.2, 0.1.7, /tmp/local)	32s
build (3.2, 0.1.7)	24s
build (3.2, 0.2.5, /tmp/local)	34s
build (3.2, 0.2.5)	28s
build (3.3, 0.1.7, /tmp/local)	48s
build (3.3, 0.1.7)	23s
build (3.3, 0.2.5, /tmp/local)	30s
build (3.3, 0.2.5)	31s
build (head, 0.1.7, /tmp/local)	28s
build (head, 0.1.7)	21s
build (head, 0.2.5, /tmp/local)	43s
build (head, 0.2.5)	34s
	20m 29s

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